Hearing devices, headsets and other hearing apparatuses must be checked and adjusted before use and possibly also during use in respect of their functionality. To this end, use is generally made of a measuring chamber in which the hearing apparatus can be exposed to defined noises and corresponding measurements can be carried out. In the broadest sense, the term measuring chamber can also be understood to signify a measuring room.
The applicant has developed a previously unpublished test method (DE 10 2005 032 272) for balancing a multi-microphone system in a hearing device. In this case, instead of a special measuring device, use is made of a programming interface (in particular a HIPRO) in conjunction with a PC. This HIPRO uses one connection to control a signal processing circuit for controlling a measuring box, and another connection to control the hearing device which must be measured. In this context, the signal processing circuit and the microphone of the measuring box can be parts of a normal hearing device, and therefore standard high-quality components can be utilized for the measuring apparatus.
An important prerequisite for the balancing of the multi-microphone system and for the implementation of this method in relation to the self-checking unit is the checking of the acoustic proofness of the test box and the basic functional checking of the multi-microphone system. This checking was previously dependent on the experience of a person skilled in the art. The speed and reliability with which the functional inefficiency of the hearing device and/or the calibration unit can be detected and resolved are dependent on this experience. Accurate analysis and error resolution can only be carried out by an expert, if at all.
Measuring the quality of voice signals is disclosed in the publication DE 699 24 743 T2. For this, a distorted signal, which corresponds to a test signal when it is distorted by the tested entity, is received and compared with the test signal in order to produce a distortion perception measurement that indicates the level at which the distortion of the signal would be perceptible for a human listener. Corresponding individual sections in the test signal and the distorted signal are selected and synchronized in order that a comparison between corresponding sections can be carried out. The results of each such comparison are combined in order to produce an overall measurement of the level at which the distortion of the signal would be perceptible for a human listener.
Furthermore, the document DE 196 34 155 A1 describes a method for simulating the acoustic quality of a room. This allows modification of sound signals which originate from a real source or generation of corresponding sound effects for recording media.